PAH refers to the condition where the pulmonary arteries in the lungs narrow, thicken, or stiffen, leading to high pressure in the pulmonary blood vessels. This requires the right ventricle of the heart to contract with increased force to pump blood from the right ventricle through the narrowed arteries to the lungs. Over time, this condition leads to right-sided heart enlargement and eventually right ventricular failure, which can be fatal. The primary cause of idiopathic pulmonary arterial hypertension is usually of unknown cause and it is a rare disease that progresses rapidly. According to data from the US National Institutes of Health (NIH), untreated patients with pulmonary arterial hypertension have an average survival rate of approximately 2.8 years.

Since pulmonary arterial hypertension cannot be cured, lifelong medication is necessary to slow down the progression of the disease. Currently, the main treatment approach involves using targeted drugs that act on the prostacyclin pathway, along with other supportive medications, to control symptoms. In later stages, medications with different mechanisms or lung transplantation may be considered. However, the side effects of existing medications include limitations on the dosage and inability to adjust to a higher dosage based on the individual’s condition. Furthermorehigh frequency of use also affects patients’ daily lives.

The L608 formulation is designed to encapsulate prostacyclin drugs in liposomes, providing localized and sustained release characteristics. It also reduces the frequency of daily dosing and allows for dosage adjustments based on the disease progression, significantly improving patients' quality of life.

Based on market strategy planning, the treatment of pulmonary arterial hypertension with L608 will primarily target the European and Asian markets, excluding North America.